Speakers

Human social interactions are regulated by a set of evolved social motives that promote functional solutions to complex problems. How do I get along with others? How do I know if I’m succeeding? How do I respond when things go wrong? Emerging models of cognition suggest that “domain-specific processing mechanisms” may not always be the cut-and-dried answer. Instead, the social mind, as with physical adaptations, was built upon and maintains links to ancestral mental structures. This process of mental scaffolding allows for ostensibly unrelated information to affect how we process and respond to problems in derived social domains. Not only might this process characterize the evolution of social motives, it also appears to be recapitulated (in a sense) during the course of development. For instance, sensorimotor touch experiences appear to lay the foundation for an abstract understanding of the world as “heavy,” “rough,” or “hard.” I will discuss research supporting the idea of both phylogenic and ontogenic scaffolding as well as how this approach can help to connect the fields of evolutionary psychology and embodied cognition.

Recent research shows that women experience nonconscious shifts across different phases of the monthly ovulatory cycle. For example, near ovulation women are attracted to symmetrical and socially dominant men and show increased desire to attend social gatherings. Building on the evolutionary logic behind such effects, my research examines how, why, and when hormonal fluctuations associated with ovulation influence women’s product choices. In a series of experiments, I demonstrate that at peak fertility women nonconsciously choose products that enhance appearance (e.g., choosing sexy rather than more conservative clothing). This hormonally-regulated effect appears to be a reflection of an ovulatory-induced increase in desire to outdo attractive rival women. Consequently, minimizing the salience of attractive women who are potential rivals suppresses the ovulatory effect on product choice. Rather than reflecting a shift in intersexual courtship motivation near ovulation, the ovulatory shift in product choice appears to reflect a shift in women’s intrasexual competitive motivation. This research provides new insights into adaptations to human ovulation and offers some of the first evidence of how, why, and when consumer behavior is influenced by hormonal factors.

Darwin’s (1871) principles of sexual selection involve two key elements –competition among members of the same sex for mates (intrasexual competition) and discriminating choice of mating partners (intersexual choice). The two most common forms are male-male competition for access to mates or for control of the resources females need to reproduce (e.g., nesting sites), and female choice of mating partners. These dynamics create sex differences in physical and behavioral traits, as well as difference in brain and cognition to the extent these differences facilitate competition or choice. The ways in which competition and choice are expressed in nonhuman species provides a principled means to examine these processes in our own species. The different ways in which men and women compete for mates and the trade-offs they make when doing so will be compared and contrasted with that of other species. The focus will be on cognitive and perceptual competencies related to intrasexual competition in both sexes and the division of labor in traditional societies and sex differences in the supporting brain systems.

Cross-species comparative analyses have long served as a vital source of information about the origins and functions of psychological traits. In the context of research on personality in non-human animals, we discuss the challenges associated with establishing cross-species equivalence for psychological traits. We show how methods from cross-cultural psychological research can be adapted to guide cross-species comparisons. Finally, we highlight the value of organizing comparative data within the framework of a phylogenetic tree structure to sharpen our thinking about the implications of cross-species evidence and to harness the power of comparative analyses.

The Endocrinology of Mating: The Role of Hormones in Overcoming Important Relationship Challenges

Differential reproductive success is the key component of the evolutionary process for all sexually reproducing organisms. Yet, successful reproduction does not always come easily. Reproduction requires one to overcome a variety of challenges associated with finding a suitable mate, staving off intrasexual rivals, and maintaining a sense of relationship commitment. Across many mammalian species, the endocrine system plays a central role in helping animals face these challenges. This talk will describe recent research on the role hormones play in romantic attraction and the maintenance of long-term relationships in humans. The studies presented in this talk examine the links between people’s mating-related motives (e.g., wanting to attract a mate or protect an existing relationship) and functionally-relevant fluctuations in steroid hormones such as testosterone and cortisol. Additional studies examine the ways in which such motives may be elicited by reproductively important hormonal shifts in other people (e.g., hormonal shifts associated with fertility in women). In sum, this talk highlights the important role hormones play in shaping mating-related motives and helping people overcome key mating-related challenges.

Intergroup aggression perpetrated by men has been a persistent feature of human societies for centuries, and may have been common enough over evolutionary time to have allowed selection to shape the neural circuitry underlying the psychology of prejudice. Because intergroup aggression poses different adaptive challenges for men and women, the psychological adaptations that operate to cope with such threats may differ between the sexes as well; and, since racial categories are often mentally represented as group-like entities, modern race bias should be understandable within this general framework. Results from several studies are consistent with this perspective, and show that (a) race bias is primarily directed at male exemplars of racial-outgroups, (b) men are more likely to be aggressively prejudiced than women, and (c) women are more likely to be fearfully prejudiced than men, particularly during the fertile phase of the menstrual cycle. Illustrations of how these systems may be operative in political attitudes and voting preferences for Barack Obama are presented. These results are consistent with the notion that the psychology of intergroup prejudice is generated by different psychological systems between men and women.

The Evolution of Irrational Decision-Making: Insights from Non-Human Primates

In spite of all our intelligence, humans are notoriously bad at making decisions. Numerous studies in judgment and decision-making have revealed that people overly weight the status quo, pay too much attention to problem-irrelevant information, over-value objects they own, and even change their preferences to fit with their previous decisions. Although much work in social psychology has examined the nature of these biased decisions in adult humans, little work to date has examined where these biases come from in the first place. My talk will explore these issues, examining the origins of our judgment and decision-making heuristics. Specifically, I will explore the possibility that some aspects of adult human irrational decision-making might be shared with non-human primates and human children. I will then attempt to use a comparative-developmental approach to directly address the origins of several classic human irrationalities, such as cognitive dissonance, loss aversion, reference dependence, and the endowment effect. I will then discuss why such irrationalities may emerge so early in human development and evolution, with the hope of providing insight into the psychological machinery that drives both accurate and biased decision-making.

Personality and social psychologists have shown increasing interest in testing evolutionary hypotheses at the level of cultures and nations. Life history data on growth and fertility, sexuality data on mate preferences and sociosexuality, and personality data on value orientations and Big Five traits all have been collected with sufficient precision to make cross-cultural comparisons viable. Combined with other culture-level indicators such as religious diversity, pathogen stress, and personality-related gene frequencies, an amassing literature on testing evolutionary hypotheses with personality and culture data has emerged. However, several important issues arise when moving from individual-level to culture-level analysis of personality. Is complete measurement invariance an absolute necessity for meaningful comparisons of personality mean scores across cultures? Or is it the case that relaxed measurement models are arguably more appropriate for theory-driven personality comparisons across cultures? Data on personality traits and romantic attachment styles from 56 nations of the International Sexuality Description Project will be used to explore and evaluate these multilevel issues facing evolutionary psychologists. Of special interest will be multilevel variation in the size of sex differences in personality. Why is it that many sex differences in personality appear larger in cultures with more progressive sex-role ideologies and egalitarian sociopolitical structures?